Bike box at 7th and Dearborn helps bikers turn left visibly

The city’s third use of bike boxes shows that SDOT has been experimenting with very different uses for bike boxes. The bike box at 7th and Dearborn in the International District will help cyclists safely turn left into the bike lane on Dearborn headed south west. Unlike the other locations at 12th and Pine and 12th and Madison, this box does not restrict right turns on red.

From what I can tell, the box serves two main purposes that should increase safety. First, the general purpose lane for straight or left turning vehicles was much too wide. A lane that is too wide is more likely to create conflicts, since drivers may be tempted to try to pass if there seems to be enough room. The bike box narrows this lane to a more standard lane width, which makes things easier and safer for people driving as much as it does for people biking.

The other way it helps improve safety is by allowing bikers to pull in front of stopped cars at a red light so they can safely make the left turn into the bike lane. It is dangerous if a person on a bike is trying to turn left while a driver is trying to go straight if that biker is not in front of the straight-going vehicle through the intersection. This bike box helps people on bikes get where they need to be.

My only concern is that people on bikes may ride in the green bike lane when the light is green, putting them to the right of car traffic that may be going straight. This is something to look out for, and I hope SDOT pays attention to this potential danger as they study this bike box usage style.

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8 Responses to Bike box at 7th and Dearborn helps bikers turn left visibly

  1. Adam Parast says:

    I think you mean West.

    “…will help cyclists safely turn left into the bike lane on Dearborn headed south.”

  2. David Amiton says:

    Is there actually a stop bar in advance of the “box” portion of the bike box? Anything indicating that a motor vehicle must stop in advance of the green? The boxes in Portland all have true stop bars with “STOP HERE” text in advance of them, which makes the message both explicit and intuitive. If the box fills with cars then it won’t be very useful for facilitating left turns.

    Also, it doesn’t look to me like the “box” portion of the bike box is actually deep enough to facilitate an easy left turn. It looks to be only 3-4′ deep, which definitely isn’t enough maneuvering room. Why didn’t SDOT simply install a box with standard depth?

    • Tom Fucoloro says:

      There is a stop line, but not the text on the road like in pdx. There is a sign with a digram showing where to stop.

      • David Amiton says:

        Tom,

        Not to pick nits (and I’m certainly no traffic engineer), but it looks like the stop line is simply a 4″ stripe (I haven’t been to the intersection post-painting, so I’m just going off the photo), which is consistent with the other Seattle bike box locations.

        Looking at SDOT’s Standard Stop Line Plans, though, the design width for a stop bar at a signalized stop is 2′. The new boxes in PDX all have these 2′ stop bars, (but the very first ones from waaay back in the day did not, among other design flaws, and they were widely considered failures), and I just wonder why SDOT is going with a 4″ instead. It seems to me that with these new (for Seattle) facilities, the devil is in the details, so why not make them as intuitive as possible? There’s an obvious quantitative difference between a 4″ and 24″ stripe, but more importantly, there’s a qualitative difference: as a person on a bike, on foot, or in a car, a 2′ stripe sends a much clearer message, and is more consistent with standard stop bar designs.

  3. mike archambault says:

    I absolutely love this concept. Thank you, SDOT for coming up with this. I hope it proves helpful to all users. My hypercritical gripe, though, is I think this is mostly for bikers riding north from Airport Way, a route I used to take regularly from work until the SoDo trail opened along the light rail line. Now I never find myself coming up 7th and I doubt many other people on bikes do or should, especially if they are headed west anyways. I get that this is probably a pilot-type of project, but I really wish SDOT would focus on where there’s actually a lot of riders or where they’re trying to establish or accommodate a primary route (like the Madison bike boxes for the Union bike lanes). 7th at Dearborn just seems like an odd spot in that regard. That said, this intersection layout indeed seems like a great candidate for such a design.

    • Tom Fucoloro says:

      While I was hanging out taking photos of it and observing how people use it, several bikes did go by. It may not be the best commuter route, but there seems to be continued demand, perhaps from areas not conveniently close to the light rail trail. I can’t wait until SDOT starts putting them everywhere they would be useful, just as standard practice. They have proven to be versatile, which Seattle needs since we have so many bizarre intersections with unique challenges.

      • mike archambault says:

        Well that’s good to hear… Hard to argue if it has the ridership numbers! I might have just been in a gripy mood. I totally agree I hope these become standard fare. Thanks for the post!

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